[PATCH v1 06/12] iio: accel: adxl313: prepare interrupt handling

[Lothar Rubusch <l.rubusch@gmail.com>]

Evaluate the devicetree property for an optional interrupt line, and
configure the interrupt mapping accordingly. When no interrupt line
is defined in the devicetree, keep the FIFO in bypass mode as before.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl313.h      |  8 ++++++++
 drivers/iio/accel/adxl313_core.c | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/drivers/iio/accel/adxl313.h b/drivers/iio/accel/adxl313.h
index ba5b5d53a0ea..c5673f1934fb 100644
--- a/drivers/iio/accel/adxl313.h
+++ b/drivers/iio/accel/adxl313.h
@@ -21,7 +21,9 @@
 #define ADXL313_REG_ACT_INACT_CTL	0x27
 #define ADXL313_REG_BW_RATE		0x2C
 #define ADXL313_REG_POWER_CTL		0x2D
+#define ADXL313_REG_INT_ENABLE		0x2E
 #define ADXL313_REG_INT_MAP		0x2F
+#define ADXL313_REG_INT_SOURCE		0x30
 #define ADXL313_REG_DATA_FORMAT		0x31
 #define ADXL313_REG_DATA_AXIS(index)	(0x32 + ((index) * 2))
 #define ADXL313_REG_FIFO_CTL		0x38
@@ -47,6 +49,11 @@
 #define ADXL313_SPI_3WIRE		BIT(6)
 #define ADXL313_I2C_DISABLE		BIT(6)
 
+#define ADXL313_REG_FIFO_CTL_MODE_MSK		GENMASK(7, 6)
+
+#define ADXL313_FIFO_BYPASS			0
+#define ADXL313_FIFO_STREAM			2
+
 extern const struct regmap_access_table adxl312_readable_regs_table;
 extern const struct regmap_access_table adxl313_readable_regs_table;
 extern const struct regmap_access_table adxl314_readable_regs_table;
@@ -67,6 +74,7 @@ struct adxl313_data {
 	struct regmap	*regmap;
 	const struct adxl313_chip_info *chip_info;
 	struct mutex	lock; /* lock to protect transf_buf */
+	int irq;
 	__le16		transf_buf __aligned(IIO_DMA_MINALIGN);
 };
 
diff --git a/drivers/iio/accel/adxl313_core.c b/drivers/iio/accel/adxl313_core.c
index 244fb2ec0b79..05e99708c2c1 100644
--- a/drivers/iio/accel/adxl313_core.c
+++ b/drivers/iio/accel/adxl313_core.c
@@ -8,11 +8,17 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 
 #include "adxl313.h"
 
+#define ADXL313_INT_NONE			0
+#define ADXL313_INT1				1
+#define ADXL313_INT2				2
+
 static const struct regmap_range adxl312_readable_reg_range[] = {
 	regmap_reg_range(ADXL313_REG_DEVID0, ADXL313_REG_DEVID0),
 	regmap_reg_range(ADXL313_REG_OFS_AXIS(0), ADXL313_REG_OFS_AXIS(2)),
@@ -438,6 +444,8 @@ int adxl313_core_probe(struct device *dev,
 {
 	struct adxl313_data *data;
 	struct iio_dev *indio_dev;
+	unsigned int regval;
+	u8 int_line;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
@@ -463,6 +471,30 @@ int adxl313_core_probe(struct device *dev,
 		return ret;
 	}
 
+	int_line = ADXL313_INT1;
+	data->irq = fwnode_irq_get_byname(dev_fwnode(dev), "INT1");
+	if (data->irq < 0) {
+		int_line = ADXL313_INT2;
+		data->irq = fwnode_irq_get_byname(dev_fwnode(dev), "INT2");
+		if (data->irq < 0)
+			int_line = ADXL313_INT_NONE;
+	}
+
+	if (int_line) {
+		/* FIFO_STREAM mode */
+		regval = int_line == ADXL313_INT2 ?  0xff : 0;
+		ret = regmap_write(data->regmap, ADXL313_REG_INT_MAP, regval);
+		if (ret)
+			return ret;
+	} else {
+		/* FIFO_BYPASSED mode */
+		ret = regmap_write(data->regmap, ADXL313_REG_FIFO_CTL,
+				   FIELD_PREP(ADXL313_REG_FIFO_CTL_MODE_MSK,
+					      ADXL313_FIFO_BYPASS));
+		if (ret)
+			return ret;
+	}
+
 	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_NS_GPL(adxl313_core_probe, IIO_ADXL313);
-- 
2.39.5